Major Depressive Disorder is defined as the presence of one of more major depressive episodes that are not better accounted for psychotic disorder or bipolar disorder. A major depressive episode is characterized by meeting five or more of the following criteria during the same 2 week period which represent a change in functioning and include at least depressed/sad mood or loss of interest and pleasure, indifference or apathy, or irritability and is usually associated with a change in a number of neurovegetative functions, including sleep patterns, appetite and body weight, motor agitation or retardation, fatigue, impairment in concentration and decision making, feelings of shame or guilt, and thoughts of death or dying (Harrison's Principles of Internal Medicine, 2000). Symptoms of a depressive episode include depressed mood; markedly diminished interest or pleasure in all, or almost all, activities most of the day; weight loss when not dieting or weight gain, or decrease or increase in appetite nearly every day; insomnia or hypersomnia nearly every day; psychomotor agitation or retardation nearly every day; fatigue or loss of energy nearly every day; feelings of worthlessness or excessive or inappropriate guilt nearly every day; diminished ability to think or concentrate, or indecisiveness, nearly every day; recurrent thoughts of death, recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide. Further, the symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, American Psychiatric Association, 1994)
Current treatment options for unipolar depression include monotherapy or combination therapy with various classes of drugs including mono-amine oxidase inhibitors (MAOI), tricyclic antidepressants (TCA), serotonin specific reuptake inhibitors (SSRI), serotonin noradrenergic reuptake inhibitors (SNRI), noradrenaline reuptake inhibitor (NRI), “natural products” (such as Kava-Kava, St. John's Wort), dietary supplement (such as s-adenosylmethionine) and others. More specifically, drugs used in the treatment of depression include, but are not limited to imipramine, amitriptyline, desipramine, nortriptyline, doxepin, protriptyline, trimipramine, maprotiline, amoxapine, trazodone, bupropion, chlomipramine, fluoxetine, citalopram, sertraline, paroxetine, tianeptine, nefazadone, venlafaxine, desvenlafaxine, duloxetine, reboxetine, mirtazapine, phenelzine, tranylcypromine, and/or moclobemide. Several of these agents including, but not limited to, serotonin reuptake inhibitors are also used when depression and anxiety co-exist, such as in anxious depression.
In the clinic, 40-50% of depressed patients who are initially prescribed antidepressant therapy do not experience a timely remission of depression symptoms. This group typifies level 1 treatment-resistant depression, that is, a failure to demonstrate an “adequate” response to an “adequate” treatment trial (that is, sufficient intensity of treatment for sufficient duration). Moreover, about approximately 30% of depressed patients remain partially or totally treatment-resistant to at least two antidepressant treatments including combination treatments. Increasingly, treatment of treatment-resistant depression includes augmentation strategies including treatment with pharmacological agents such as, antipsychotics (such as quetiapine, aripiprazole, olanzapine, risperidone, and the like), lithium, carbamazepine, and triiodothyronine, and the like; adjunctive electroconvulsive therapy; adjunctive transcranial magnetic stimulation; etc.
Suicide, also known as completed suicide, is the “act of taking one's own life”. Attempted suicide or non-fatal suicidal behavior is self-injury with the desire to end one's life that does not result in death. Suicidal ideations are thoughts of ending one's life but not taking any active efforts to do so.
Suicidal ideation is the medical term for thoughts about or an unusual preoccupation with suicide. The range of suicidal ideation varies greatly from fleeting to detailed planning, role playing, and unsuccessful attempts, which may be deliberately constructed to fail or be discovered, or may be fully intended to result in death. Although most people who undergo suicidal ideation do not go on to make suicide attempts, a significant proportion do. Suicidal ideation is generally associated with depression; however, it seems to have associations with many other psychiatric disorders, life events, and family events, all of which may increase the risk of suicidal ideation.
Suicidal ideation—may include, for example, suicidal thoughts—but may also include other related signs and symptoms. Some symptoms or co-morbid conditions may include unintentional weight loss, feeling helpless, feeling alone, excessive fatigue, low self-esteem, presence of consistent mania, excessively talkative, intent on previously dormant goals, feel like one's mind is racing. The onset of symptoms like these with an inability to get rid of or cope with their effects, a possible form of psychological inflexibility, is one possible trait associated with suicidal ideation. They may also cause psychological distress, which is another symptom associated with suicidal ideation. Symptoms like these related with psychological inflexibility, recurring patterns, or psychological distress may in some cases lead to the onset of suicidal ideation. Other possible symptoms and warning signs include: hopelessness, anhedonia, insomia, depression, severe anxiety, angst, impaired concentration, psychomotor agitation, panic attack and severe remorse.
Scales used in the evaluation of suicidal ideation include Beck Scale for Suicide Ideation (BSS), Columbia Suicide Severity Rating Scale and The Kessler Psychological Distress Scale (K10, which test does not measure suicidal ideation directly, but there may be value in its administration as an early identifier of suicidal ideation. High scores of psychological distress are also, in some cases associated with suicidal ideation.
There are also several psychiatric disorders that appear to be comorbid with suicidal ideation or considerably increase the risk of suicidal ideation. The following disorders have been shown to be the strongest predictors of suicidal ideation/disorders in which risk is increased to the greatest extent: major depressive disorder (MDD), dysthymia, bipolar disorder, post traumatic stress disorder (PTSD), personality disorders, psychosis (anxiety or detachment from reality), paranoia, schizophrenia and drug abuse.
The main treatments for suicidality and/or suicidal ideation include: hospitalization, outpatient treatment, and medication. Hospitalization allows the patient to be in a secure, supervised environment to prevent their suicidal ideation from turning into suicide attempts. In most cases, individuals have the freedom to choose which treatment they see fit for themselves. However, there are several circumstances in which individuals can be hospitalized involuntarily, including circumstances where an individual poses danger to self or others and where an individual is unable to care for one's self.
Outpatient treatment allows individuals to remain at their place of residence and receive treatment when needed or on a scheduled basis. Before allowing patients the freedom that comes with outpatient treatment, physicians evaluate several factors of the patient. These factors include the patient's level of social support, impulse control and quality of judgment. After the patient passes the evaluation, they are often asked to consent to a “no-harm contract”. This is a contract formulated by the physician and the family of the patient. Within the contract, the patient agrees not to harm themselves, to continue their visits with the physician, and to contact the physician in times of need. These patients are then checked on routinely to assure they are maintaining their contract and staying out of troublesome activities.
There are also a number of different pharmacological treatment options for those experiencing suicidal ideation. However, prescribing medication to treat suicidal ideation can be difficult. One reason for this is because many medications lift patients' energy levels before lifting their mood. This puts them at greater risk of following through with attempting suicide. Additionally, if a patient has a co-morbid psychiatric disorder, it may be difficult to find a medication that addresses both the psychiatric disorder and suicidal ideation. Therefore, the medication prescribed to one suicidal ideation patient may be completely different than the medication prescribed to another patient. However, there are several medications that seem to work fairly well for treating suicidal ideation, more particularly antidepressants, including fluoxetine (PROZAC), sertraline (ZOLOFT), paroxetine (PAXIL), fluvoxamine (LUVOX), venlafaxine (EFFEXOR) and nefazodone (SERZONE).
Although research is largely in favor of the use of antidepressants for the treatment of suicidal ideation, in some cases antidepressants are claimed to be associated with increased suicidal ideation. Upon the start of using antidepressants, many clinicians will note that sometimes the sudden onset of suicidal ideation may accompany treatment. This has caused the Food and Drug Administration (FDA) to issue a warning stating that sometimes the use of antidepressants may actually increase the thoughts of suicidal ideation.
Ketamine (a racemic mixture of the corresponding S- and R-enantiomers) is an NMDA receptor antagonist, with a wide range of effects in humans, including analgesia, anesthesia, hallucinations, dissociative effects, elevated blood pressure and bronchodilation. Ketamine is primarily used for the induction and maintenance of general anesthesia. Other uses include sedation in intensive care, analgesia (particularly in emergency medicine and treatment of bronchospasms. Ketamine has also been shown to be efficacious in the treatment of depression (particularly in those who have not responded to other anti-depressant treatment). In patients with major depressive disorders, ketamine has additionally been shown to produce a rapid antidepressant effect, acting within two hours.
The S-ketamine enantiomer (or S-(+)-ketamine or esketamine) has higher potency or affinity for the NMDA reception and thus potentially allowing for lower dosages; and is available for medical use under the brand name KETANEST S.
There remains a need to provide an effective treatment for depression, more particularly treatment resistant depression and/or for the treatment of suicidality, suicidal ideations, and for the prevention of suicide, particularly in the first hours and days after the onset of a major depressive episode.